Abstract: Cornea serves as the partial front barrier and major light reflection organ of the eye. The integrity of corneal surface is essential for ocular function. Injuries or congenital diseases could significantly destruct the homeostasis of the ocular surface, especially the microenvironment of limbal epithelial stem cells (LESCs), and will eventually cause dysfunction of corneal regeneration and diminish of LESCs. The loss of LESCs by different reasons are named limbal stem cell deficiency (LSCD), which is one of the leading cause of vision loss worldwide. To restore the corneal surface, LESC transplantation in the form of tissue or cell cultures is currently a viable and promising method to treat LSCD. In this review, we aim to introduce the characters and niche of LESCs, and discuss different aspects of its application in cornea surface reconstruction.

Abstract: To describe the current aging population in China and globally, especially as it applies to age-related macular degeneration (AMD). To review the current standards of care for treating both wet (exudative) eAMD and dry (atrophic) aAMD. And to introduce a model for experimentation that is based on the Age-Related Eye Disease Study (AREDS) using eye bank tissue. A literature search that outlines current aging populations, standards of clinical treatment as defined by large, multicenter, randomized clinical trials that present level-I data with a low risk for bias. An experimental model system of AMD is presented that enables scientific analysis of AMD pathogenesis by applying grading criteria from the AREDS to human eye bank eyes. Analysis includes proteomic, cellular, and functional genomics. The standard of care for the treatment of eAMD is currently defined by the use of several anti-vascular endothelial growth (anti-VEGF) agents alone or in combination with photodynamic therapy. Monotherapy treatment intervals may be monthly, as needed, or by using a treat-and-extend (TAE) protocol. There are no proven therapies for aAMD. AMD that is phenotypically defined at AREDS level 3, should be managed with the use of anti-oxidant vitamins, lutein/zeaxanthin and zinc (AREDS-2 formulation). By understanding the multiple etiologies in the pathogenesis of AMD (i.e., oxidative stress, inflammation, and genetics), the use of human eye bank tissues graded according to the Minnesota Grading System (MGS) will enable future insights into the pathogenesis of AMD. Initial AMD management is with lifestyle modification such as avoiding smoking, eating a healthy diet and using appropriate vitamin supplements (AREDS-2). For eAMD, anti-VEGF therapies using either pro re nata (PRN) or TAE protocols are recommended, with photodynamic therapy in appropriate cases. New cellular information will direct future, potential therapies and these will originate from experimental models, such as the proposed eye bank model using the MGS, that leverages the prospective AREDS database.

Abstract: Autoimmune retinopathy (AIR) refers to both paraneoplastic and non-paraneoplastic forms of a rare, acquired retinal degeneration thought to be mediated by the production of antiretinal antibodies. However, the mechanisms underlying AIR pathogenesis are incompletely understood, and it remains a diagnosis of exclusion given the lack of definitive testing as well as its protean clinical presentation. This review summarizes the current literature on the epidemiology, diagnosis, and management of AIR, with a focus on non-paraneoplastic disease and the potential role of immunomodulatory therapy. A recent expert consensus statement on diagnosis and management of non-paraneoplastic AIR served as a framework for interpreting the limited data available, a process that was complicated by the small sample sizes, heterogeneity, and retrospective nature of these studies. Additional work is needed to characterize AIR patients on the basis of cytokine and immunogenetic profiling; to establish the pathogenicity of antiretinal antibodies; and to standardize treatment regimens as well as assessment of clinical outcomes.

Abstract: Effective and safe electrical stimulation of the retinal ganglion cells is at the heart of retinal prosthesis design. However, the effectiveness and safety demand of the electrical stimulation is often at odds against each other. Besides, the nerve fiber layer above retinal ganglion cells limits the spatial resolution of stimulation. Also, current retinal prosthesis still cannot selectively activate the ON or OFF visual pathways, thus cannot relay the correct luminance information to the brain. With decades of development, the stimulation protocol for retinal implants began to tackle these problems. We believe that a novel design of electrical stimulation scheme, combined with gene therapy technique, can improve the selectivity and spatial resolution of retinal implants and further lower the damage caused by electric stimulation.

Abstract: Age-related macular degeneration (AMD) is a leading cause of blindness worldwide. AMD most commonly affects older individuals and is characterized by irreversible degeneration of the retinal pigment epithelium and neurosensory retina. Currently, there are limited treatment options for dry AMD outside of lifestyle modification and nutrient supplementation. Risuteganib [Luminate (ALG-1001), Allegro Ophthalmics, CA, USA] is an intravitreally administered inhibitor of integrin heterodimers αVβ3, αVβ5, α5β1, and αMβ2. It is currently undergoing clinical trials for the treatment of dry AMD and diabetic macular edema (DME). Preclinical studies have shown that risuteganib has an effect on the pathways for angiogenesis, inflammation, and vascular permeability. Ongoing clinical trials have had promising results showing improvements in patient best corrected visual acuity (BCVA) and reduced central macular thickness measured by optical coherence tomography (OCT). There is a pressing need for treatments for dry AMD and while risuteganib appears to have a potential benefit for patients, more data are needed before one can truly evaluate its efficacy. This narrative review provides a concise summary of the most up to date data regarding the proposed mechanism of action of risuteganib in the treatment of nonexudative AMD and DME as well as the results from recent phase 1 and phase 2 clinical trials.

Abstract: Bioengineered materials are used as a substitute in many fields of medicine, especially in plastic surgery and in burns. In ophthalmic plastic surgery they can be used for covering large tissue defects or as a tarsal plate substitute, in cases when it is not possible to use conventional surgical techniques. We have searched PubMed and Web of Science scientific databases. We can generally categorize skin substitutes by the type of tissue used—we distinguish autografts, allografts, and xenografts. There are also completely synthetic substitutes. The aim of our article was to summarize the current state of knowledge and to sum up all the clinical applications of bioengineered materials in the periocular region. There are only a few scientific articles about this topic and lack of prospective randomized studies aimed on use of bioengineered materials in periocular region. Nevertheless, there are many articles describing successful case reports or case reports series. According to literature, bioengineered materials are the most commonly used in big traumas or large surgical defects, especially in oculoplastic tumour surgery. Bioengineered dermal substitutes are not frequently used in the periocular region. Dermal substitutes are useful, when it is not possible to close the defect with any other conventional surgical technique.

 Conjunctival flaps have previously proven to be effective in preserving the globe for individuals with severe ocular surface disease. Infectious keratitis, neurotrophic keratitis, nontraumatic corneal melts, descemetoceles, perforations, and corneal burns are all indications for this procedure. The flaps promote nutrition, metabolism, structure, and vascularity, as well as reduce pain, irritation, inflammation, and infection. Furthermore, patients avoid the emotional and psychological repercussions of enucleation or evisceration, while requiring fewer postoperative medications and office visits. Currently, fewer flaps are performed due to the emergence of additional therapeutic techniques, such as serum tears, bandage lenses, corneal grafting, Oxervate, amniotic membrane, and umbilical cord grafting. However, despite newer conservative medical methods, conjunctival flaps have been demonstrated to be useful and advantageous. Moreover, future technologies and approaches for globe preservation and sight restoration after prior conjunctival flaps are anticipated. Herein, we review the history, advantages, and disadvantages of various surgical techniques: Gundersen’s bipedicle flap, partial limbal advancement flap, selective pedunculated conjunctival flap with or without Tenon’s capsule, and Mekonnen’s modified inferior palpebral-bulbar conjunctival flap. The surgical pearls and recommendations offered by the innovators are also reviewed, including restrictions and potential complications. Procedures for visual rehabilitation in selective cases after conjunctival flap are reviewed as well.